Manufacture of secondary-battery plates of the planté type.



- Patented luiy I5. 1902. H. m. MARTIN.

@HANUFACTURE 0F SECUNDABY BATTER-Y PLATES 0F m5 RLAnT TYPE.

{Application filed July 80, 1901.!

(No Model.) I

m5 uomus Pmas co, Pi-ccruurnm. WASHINGTON. u. c.

UNITED STATES PATENT OFFICE.

HAROLD M. MARTIN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THEELECTRIC STORAGE BATTERY COMPANY, OF PHILADELPHIA, PENNSYLVANIA, ACORPORATION OF NEW JERSEY.

MANUFACTURE OF SECONDARY-BATTERY PLATES OF THE PLANTL TYPE.

SPECIFICATION formingpart of Letters Patent N 0. 704,751, dated July 15,1902.

Application filed July 30,1901. Serial in 70.259. (N0 model.)

T0 at whom, it may concern:

Be it known that I, HAROLD M. MARTIN, a

citizen of the United States, residing at Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in the Manufacture of Secondary or Storage BatteryPlates of the Plan t Type, of which the following is a specification.

In manufacturing storage-batteryplatesof the Plant type the lead of thelead plates is converted into peroxid of lead by electrolytic action.This process is frequently designated a factory-forming process asdistinguished from the processof charging the battery after itscompletion and while it is in use. Formerly the factory formation ofperoxid of lead was effected by electrolytic action in a bath slightlyacidulated withjsulfuric acid. Such was Plants method. Du Jardin, UnitedStates Patent No. 497,869, and Van de Poole, United States Patent No.285,529, suggested means for hastening and improving the factoryformation of peroirid of lead on the plates; but their methods did notgo into commercial use. Subsequently Griscom in United States Patent No.515,333 pointed out a process for the accomplishment of the factoryformation, which process has.

been widely adopted. Prior to my invention the state of the art was thatit hadbeen pointed out that current density and the charactor of theelectrolyte were important factors in producing the factory formation ofperoxid of lead in a rapid manner. The Griscom patent above referred toaccurately states the proper electrolyte and the proper current densityfor the successful production of peroxid of lead on the plates in thefactory formation; but in practicing the process of the Griscom patentdifferent kinds of useful peroxid are produced in the factory formation.

It is the object of the present invention to improve upon the process ofthe Griscom patent in such a way that it is possible to produce anypredetermined character of useful peroxid and in that way to make theproduct more uniform.

To these and other ends hereinafter set forth my invention comprisesthat improvement inthe Griscom process for the factory formation ofperoxid of lead on the plates which consistsin controlling thetemperature of the electrolyte.

To practice my invention I control the temperature of the electrolyte,whereby the peroxid produced in the factory formation can be'madeuniform and of the same kind.

For example, I proceed as is set forth i n the Griscom patentabovereferred to, wherein it is pointed out how two of thefactors-namely, the current density and the strength of thesolutionenter into the result; but while so proceeding and in accordancewith my invention I control the temperature of the electrolyte, and byso doing I amZenabled to produce in the factory formation uniformperoxid of any predetermined kind. As an illustration of the temperatureI may'say that I keep the electrolyte below 115 Fahrenheit; but, as Ihave stated, it is possible by changing the upper limit of-thetemperature to produce as Toften as may be desired peroxid of differentkind for each "temperature, but of the same kind for the sametemperature.

In the drawing I have illustrated diagrammatically a plan view of onekind of apparatussuitaolefor the practice of my invention. In thedrawing, 1 is a suitabletank adapted to contain the electrolyte," whichmay be substau'tially theelectroly'te described i 11116 Griscom patent.

2 represents electrical connections for supplyingcurrent which may be atsubstantially the current density set forth in the Griscom patent. V

3 represents the plates upon which the peroxid is to be formed by thefactory-formation process.

4 represents dummy plates, which arecommonly used in this process.

5 is a coil of pipe through which a suitable medium, as water, is causedto circulate. This coil of pipe is immersed inthe'electrolyte, and it isan example of means for controlling the temperature of the same.

It will be obvious to those skilled in the art to which the inventionrelates that modifications may be made in details without departing fromthe spirit thereof. Hence I do not limit myself to the preciseconstruction and arrangement of parts hereinabove set forth, andillustrated in the accompanying drawings; but,

Having thus described the nature and ob jects of the invention, what Iclaim as new, and desire to secure by Letters Patent, is-

1. In the rapid factory-formation process of making peroxid of leadonbattery-plates which consists in subjecting the plates to e1ec trolyticaction in an electrolyte capable of producing the rapid formation ofperoxid from metallic lead, that improvement which consists incontrolling the temperature of the electrolyte during the formation,substantially as described.

